Tool used in forming a chip scale package

Abstract

A method of assembling a plurality of semiconductor chips is provided. A portion of a semiconductor wafer containing the plurality of chips is provided. Each of the plurality of chips has a contact pattern area including a pattern of contacts on a surface of the chip. A respective section of a dielectric interposer is assembled to each respective one of the plurality of chips individually, without detaching the plurality of chips from the portion of the semiconductor wafer. Each section of interposer has a plurality of bonding pads near an outer periphery of the section, so that each bonding pad lies near the contact pattern area of the corresponding one of the plurality of chips. Each bonding pad is wire bonded to a respective one of the contacts on the front surface of the corresponding one of the plurality of chips. The bonding step includes: (1) bonding one end of each wire to a respective bonding pad of the interposer using micro-resistant welding or ultrasonic bonding, and (2) bonding the other end of each wire to a respective contact of the chip using ultrasonic bonding. If a defective bond is detected, a wire may be removed and replaced by wire bonding. An encapsulant is applied to encapsulate the wires on each of the plurality of chips. The encapsulated chips are cut from the semiconductor wafer. Wires may be bonded at the corners of the chip, and need not be perpendicular to the sides of the chip.

What is claimed is: 
     
       1. A wedge bonding tool for use in a wire bonder, comprising: a body portion made of an electrically conductive material, the body portion including first and second electrodes and an insulating spacer separating the first and second electrodes; and   a wedge working tip on one end of said body portion, the wedge working tip having a foot and a wire hole through the wedge working tip for directing a wire under the foot, one end of the first conductor forming a first portion of said wedge working tip, one end of the second conductor forming a second portion of said wedge working tip,   wherein both electrical energy and ultrasonic energy are provided to the wire at the wedge working tip.   
     
     
       2. A wedge bonding tool according to claim 1, wherein the foot of the wedge working tip includes the first portion of the wedge working tip. 
     
     
       3. A wedge bonding tool according to claim 1, wherein the first and second conductors are formed from either one of the materials in the group consisting of molybdenum, tungsten carbide and osmium. 
     
     
       4. A wedge bonding tool for use in a wire bonder having both an ultrasonic energy source and an electrical energy source, the wedge bonding tool comprising: a body portion made of an electrically conductive material, the body portion including first and second electrodes and an insulating spacer separating the first and second electrodes; and   a wedge working tip on one end of said body portion, the wedge working tip having a foot and a wire hole through the wedge working tip for directing a wire under the foot, the wedge working tip conducting electrical energy from the electrical energy source to a first end of the wire and ultrasonic energy from the ultrasonic energy source to a second end of the wire.   
     
     
       5. A wedge bonding tool according to claim 4, wherein the electrical energy is applied to the second end of the wire after the ultrasonic energy is applied to the second end of the wire. 
     
     
       6. A wedge bonding tool according to claim 1, wherein the electrical energy is applied to a first end of the wire and the ultrasonic energy is applied to a second end of the wire. 
     
     
       7. A wedge bonding tool according to claim 6, wherein the electrical energy is applied to the second end of the wire after the ultrasonic energy is applied to the second end of the wire.